小剂量地塞米松对颞叶癫痫大鼠海马NR_2A、NR_2B表达的影响  

Effect of low-dose dexmethasone on the expression of NR_2A and NR_2B in hippocampus in temporal lobe epileptic rat

作　　者：王美娜[1] 李丰[1] 李海波[1] 李淞[2] 张淑琴[3] 梁建民[1] 

机构地区：[1]吉林大学白求恩第一医院儿科,吉林长春130021 [2]吉林省人民医院神经内科,吉林长春130021 [3]吉林大学白求恩第一医院神经内科,吉林长春130021

出　　处：《中风与神经疾病杂志》2013年第12期1067-1070,共4页Journal of Apoplexy and Nervous Diseases

基　　金：中国博士后基金(2005037033);吉林省自然科学基金(201015147);长春市科技局儿科诊疗中心重点专科建设项目(2010120)

摘　　要：目的探讨地塞米松(Dex)对颞叶癫痫大鼠海马NMDA受体亚单位NR2A、NR2B表达的影响。方法将雄性Wistar大鼠随机分为正常组、假手术组(Sham组)、生理盐水预处理后颞叶癫痫点燃组(TLE组)和小剂量Dex短期预处理后颞叶癫痫点燃组(Dex组)。应用海人酸杏仁核点燃建立经典颞叶癫痫模型,采用原位杂交方法检测点燃或假手术后海马神经元NR2AmRNA、NR2BmRNA的时空表达。结果正常组和Sham组海马总体和各区NR2AmRNA阳性细胞表达无差异(P>0.05);与Sham组比较,TLE组24h、7d、14d、21d NR2AmRNA表达增高(P<0.05),点燃后21d以海马CA1区和齿状回(DG)表达增高为主(P<0.05);Dex组在点燃后6h明显高于TLE组,在7d、14d、21d低于TLE组(P<0.05),点燃后21d海马CA1区和DG均低于TLE组(P<0.05)。正常组和Sham组CA3区NR2BmRNA表达高于CA1区和DG(P<0.05),TLE组和Dex组DG表达高于CA1和CA3区(P<0.05),Dex组21d海马各区表达均高于TLE组(P<0.05)。结论颞叶癫痫大鼠海马NR2A和NR2B表达出现时空表达变化。小剂量Dex可减轻颞叶癫痫引起的海马NR2A和NR2B表达失衡,可能是其发挥抗颞叶癫痫和脑保护作用的机制之一。Objective To explore the effect of dexmethasone on the expressions of the subunits NR2A and NR2B of NMDA receptors in hippocampus in temporal lobe epileptic rats after kindling. Methods Male Wistar rats were randomly divided into normal group, sham group, natrium saline pretreatment group before kindling （TLE group） and Dex pretreat- ment group prior to be kindled （ Dex group）. Typical temporal lobe epileptic model was kindled by Kainic acid （KA） mi- croinjected into right Nucleus amygdalae. In situ hybridization was used to spatio-temporally observe the expression of NR2AmRNA and NR2BmRNA in hippocampus after kindling or sham operating in rats. Results There was no difference of positive cell count （PCC） of NR2 AmRNA expression in hippocampus between Sham group and normal group both in total and in each hippocampal subarea （P 〉 0.05 ）. Compared to Sham group, NR2 AmRNA expressed higher at 24h,7d, 14d,21 d after kindling （P 〈0.05）,and enhanced in CAp and DG regions both in total and on 21d after kindling （P 〈0.05）. While, compared to TLE group, NR2 AmRNA increased at 6h in Dex group （ P 〈 0.05 ）, and decreased on 7d, 14d,21 d after kindling （P 〈0.05） ,especially declined in CA1 and DG regions both in total and on 21d in Dex group than that of TLE group after kindling （P 〈 0.05 ）. In general, NR2 BmRNA expressed higher in CA3 region than that in CA1 and DG regions in Sham and normal groups （P 〈0.05）. However, in TLE and Dex groups, its expression was increased in DG than that in CA1 and CA3 regions （P 〈 0.05 ）, and it was enhanced in each subareas in hippocampus in Dex group than that of TLE group （P 〈 0.05）. Conclusion There are temporal and spatial changes of NR2 A and NR2 B expressions in hippocampus in TLE rats. l^w-dose dex may play its antiepileptic and protective role via alleviating temporospatial unbalance of the expression of NR2A and NR2B in hippocampus in temporal lobe epilepsy.

关 键 词：地塞米松 癫痫 海人酸 点燃 NMDA受体 

分 类 号：R742.1[医药卫生—神经病学与精神病学]